Field of the Invention
Exemplary embodiments of the present invention relate to a system and method for controlling a fuel cell of a vehicle, which secures reliability of variable pressure control through prevention of fuel cell performance deterioration and system malfunction.
Description of Related Art
To prevent performance deterioration of a fuel cell stack, humidity maintenance control is compulsory. Particularly, in a high-temperature/high-output region, the stack is liable to being dried out due to the humidity limit performance of the fuel cell. Accordingly, a method to limit an output has been used which may, however, cause driver's dissatisfaction to reduce the output performance of the vehicle for the prevention of stack deterioration. Thus, the present invention proposes a method of improving a humidity situation by operating a fuel cell system without using the method to limit an output.
In the fuel cell system as illustrated in FIG. 3, performance deterioration occurs due to the humidity limit performance in a high-output/high-temperature situation, and thus the output is deteriorated from state 1 to state 2. To prevent such performance deterioration, a method to pre-limit an output has also been proposed. However, this method accompanies reduction of the operation performance, and thus is unable to provide a basic solution. Further, many methods to increase operation pressure have been proposed to improve the humidity state of the system.
To increase the operation pressure, an air compressor and an opening adjustment valve may be used. However, this may increase power consumption of an accessory drive and may cause noise to occur in the air compressor. In one developed technology of the related art, a method to perform pressure operation only on a specific condition that a dry-out situation is sensed by measuring moisture content of the stack or estimating humidity has been proposed. Like the present invention, this technology adopts the variable pressure control. However, in performing the variable pressure control, the present invention proposes an improved technology to secure reliability for flow rate/pressure control.
The terms described as a background technology of the present invention are merely to improve understanding of the background of the present invention, and should not be accepted to concede that the terms correspond to the related art already known to those of ordinary skill in the art.